<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>变量</title>
</head>
<body>
    
</body>
<script>
  var num1 =070;
  var num2 =0x1f;
  console.log(num1,num2)
  console.log(isFinite(21));
  console.log(isFinite("Hello world"));
</script>
</html>